Motor mount I.D. - What's the application?

Hey guys, I pulled these mounts from my parts pile thinking I was going to use them on my 75 D300 440 swap but after looking closer they appear to be for a small block. I would assume they are truck mounts still but wasn't sure if maybe they were for a motorhome or if there was a difference between 2WD and 4WD truck mounts, etc. Just want to know what they fit for future reference or so I can send them off to someone that can use them. For what it's worth, one is stamped "LR" and the other is stamped "RT-318". Thanks! Trent